[The Development of SpCas9 Variants with High Specificity and Efficiency Based on the HH Theory].

Streptococcus pyogenes Cas9 (SpCas9) is the most popular tool in gene editing; however, off-target mutagenesis is one of the biggest impediments in its application. In our previous study, we proposed the HH theory, which states that sgRNA/DNA hybrid (hybrid) extrusion-induced enhancement of hydrophobic interactions between the hybrid and REC3/HNH is a key factor in cleavage initiation. Based on the HH theory, we analyzed the interactions between the REC3 domain and hybrid and obtained 8 mutant sites. We designed 8 SpCas9 variants (V1-V8), used digital droplet PCR to assess SpCas9-induced DNA indels in human cells, and developed high-fidelity variants. Thus, the HH theory may be employed to further optimize SpCas9-mediated genome editing systems, and the resultant V3, V6, V7, and V8 SpCas9 variants may be valuable for applications requiring high-precision genome editing.

[Efficacy of adjuvant programmed cell death 1 (PD-1) monoclonal antibody immunotherapy in Chinese patients with resected stage â ¡-â ¢ melanoma].

Objective: To explore the efficacy of adjuvant programmed cell death 1 (PD-1) monoclonal antibody immunotherapy in Chinese patients with resected stage Ⅱ-Ⅲ melanoma. Methods: A total of 296 patients who underwent radical surgery for stage Ⅱ-Ⅲ cutaneous orlimb melanoma at Fudan University Shanghai Cancer Center and Shanghai Electric Power Hospital between 2017 and 2021 and received adjuvant PD-1 monoclonal antibody immunotherapy, low-dose interferon (IFN), or observational follow-up were enrolled in this study. Patients were divided into the PD-1 monoclonal antibody group (164 cases) and the IFN or observation group (IFN/OBS group, 132 cases) based on postoperative adjuvant treatment methods. Patients' disease recurrence and survival were observed. Results: Among the 296 patients, 77 had cutaneous melanoma and 219 had limb melanoma; 110 were stage Ⅱ and 186 were stage Ⅲ. Among stage Ⅱ patients, the median recurrence-free survival (RFS) in the PD-1 monoclonal antibody group (46 cases) did not reach, while the median RFS in the IFN/OBS group (64 cases) was 36 months. The 1-year RFS rates were 85.3% and 92.1% and the 2-year RFS rates were 71.9% and 63.7% in the PD-1 monoclonal antibody group and the IFN/OBS group, respectively, with no statistically significant difference (P=0.394). Among stage Ⅲ patients, the median RFS rates in the PD-1 monoclonal antibody group (118 cases) and the IFN/OBS group (68 cases) were 23 and 13 months, respectively. The 1-year RFS rates were 70.0% and 51.8% and the 2-year RFS rates were 51.8% and 35.1%in the PD-1 monoclonal antibody group and the IFN/OBS group, respectively, with a statistically significant difference (P=0.010). Stratified analysis showed that the advantage of PD-1 monoclonal antibody adjuvant therapy in improving RFS persisted in the subgroups of primary ulceration (HR=0.558, 95% CI: 0.348-0.893), lymph node macroscopic metastasis (HR=0.486, 95% CI: 0.285-0.828), stage ⅢC (HR=0.389, 95% CI: 0.24-0.63), and the subgroup without BRAF/c-Kit/NRAS gene mutations (HR=0.347, 95% CI: 0.171-0.706). In terms of recurrence patterns, in stage Ⅱ patients, the recurrence and metastasis rate was 15.2% (7/46) in the PD-1 monoclonal antibody group, significantly lower than the IFN/OBS group [43.8% (28/64), P=0.002]. In stage Ⅲ melanoma patients, the recurrence and metastasis rate was 42.4% (50/118) in the PD-1 monoclonal antibody group, also lower than the IFN/OBS group [63.2% (43/68), P=0.006]. Conclusions: In real-world settings, compared with patients receiving low-dose IFN adjuvant therapy or observational follow-up, PD-1 monoclonal antibody immunotherapy can reduce the recurrence and metastasis rate of cutaneous and limb melanoma, and prolong the postoperative RFS of stage Ⅲ cutaneous and limb melanoma patients. Patients with a heavier tumor burden benefit more from immunotherapy.

[Application of Rotarex catheter system in femoropopliteal artery stenosis accompanied with thrombosis].

OBJECTIVE: To evaluate the effectiveness and safety of Rotarex catheter system in treating femoropopliteal artery stenosis accompanied with thrombosis. METHODS: From Jun. 2017 to Dec. 2019, the clinical data of 32 femoropopliteal artery stenosis accompanied with thrombosis cases treated with Rotarex catheter system were retrospectively analyzed. There were 23 males and 9 females aged from 50 to 89 years and the mean age was (70.7±10.3) years. Six cases had acute course of disease (≤2 weeks), 17 cases had subacute course of disease (>2 weeks, ≤3 months), and 9 cases had chronic course of disease (>3 months). Mean lesion length was (23.4±13.7) cm, mean occlusion length was (19.9±13.3) cm, and in-stent occlusion 7 cases. The superficial femoral artery (SFA) was involved in 13 cases, the popliteal artery (PA) was involved in 8 cases, and both SFA and PA were involved in the other 11 cases. All the cases were treated with Rotarex catheter system. When necessary, suction with large lumen catheter was enabled. Residual stenosis was treated with percutaneous transluminal angioplasty (PTA). Drug-coated balloon (DCB) was only used in patients with financial status, and stent was used only when it was necessary. Heparin was used for 24 h after procedures, and after that, antiplatelet agents were used. Doppler ultrasonography was taken during the followed-up. RESULTS: Technical success was 100%, and mean procedure time was (107.4±21.5) min. 8F (1F≈0.33 mm) and 6F Rotarex catheter were used in 27 and 5 cases respectively. In 27 cases, forward flow was obtained immediately after debulking with Rotarex catheter, and in the other 5 cases, suction with large lumen catheters were used. PTA was used in all 32 cases. DCB were used in 8 cases, of which 4 were used in in-stent stenosis. Twelve cases were implanted stents. There were no perioperative deaths. The only one procedure related complication was distal embolism. We took out the thrombus with guiding catheter. In all cases, mean hospital stay were (4.6±1.5) d. The ankle brachial index increased from 0.32±0.15 to 0.86±0.10 after treatment (t=-16.847, P < 0.001). The Rutherford stages decreased significantly (Z=-4.518, P < 0.001). All the patients were followed up for 6.0-36.0 months, and the median time was 16.0 months. 2 cases stopped antiplatelet agents, which resulted in acute thrombosis. Another percutaneous mechanical thrombectomy and PTA were taken in one of them. Two cases died of cardiovascular disease during the follow-up, and no amputation was observed. Target lesion restenosis occurred in 7 cases during the follow-up, and target lesion revascularization (TLR) was taken in two of them. CONCLUSION: In treating femoropopliteal artery stenosis accompanied with thrombosis, Rotarex catheter can remove thrombus effectively, and that can expose underlying lesions and reduce stent use and complications rates. It is a safe and effective method.

[Influencing factors for electronic cigarette use among Chinese adolescent students: a Meta-analysis].

Objective: To explore the influencing factors of electronic cigarette use among adolescent students in China. Methods: We searched CNKI, Database of Chinese sci-tech periodicals (VIP), Wan-fang database, PubMed, Web of Science and ScienceDirect for potentially relevant articles published from the inception to March 20th, 2023. The Metagen package in R was used for Meta-analysis. Results: A total of 19 publications with a sample size of 5 336 017 were identified. The results showed that electronic cigarette use among Chinese adolescent students was associated with gender (OR=2.41, 95%CI: 2.03-2.86), close friends smoking (OR=3.02, 95%CI: 2.08-4.39), current smoking (OR=11.26, 95%CI: 4.35-29.18), friends using electronic cigarettes (OR=5.19, 95%CI: 2.01-13.38), thinking smoking makes young people look more attractive (OR=2.00, 95%CI: 1.35-2.97), type of school (OR=2.10, 95%CI: 1.59-2.78), thinking smoking makes people feel more comfortable in social situations (OR=3.58, 95%CI: 2.99-4.28), other tobacco use (OR=5.53, 95%CI: 3.33-9.20), and ever experimented with cigarette use (OR=9.32, 95%CI: 4.38-19.80). Conclusion: The influencing factors for electronic cigarette use among adolescent students in China include gender, close friends smoking, current smoking, friends using electronic cigarettes, thinking smoking makes young people look more attractive, type of school, thinking smoking makes people feel more comfortable in social situations, other tobacco use, and ever experimented with cigarette use.

[Characteristics of slow wave activity of sleep electroencephalogram and the changes of slow wave activity after adenotonsillectomy in children with severe obstructive sleep apnea].

Objective: To investigate the characteristics of slow wave activity (SWA) during sleep and the changes of SWA after adenotonsillectomy in children with severe obstructive sleep apnea (OSA). Methods: A total of 24 children with severe OSA, who completed adenotonsillectomy in Sleep Center of Beijing Children's Hospital and 26 control children category matched for age and sex and excluded from OSA were included as subjects from May 2018 to December 2019. The subjects underwent overnight PSG, as well as SWA analysis of sleep electroencephalogram. The differences of PSG indexes and SWA intensity between children with severe OSA and control children, before and after operation in severe OSA children were compared and the correlations between SWA intensity and PSG indexes were analyzed. Results: The age of the children with severe OSA before surgery was (6.1±1.7) years, including 20 males (83.3%), and the interval M(Q1,Q3) between surgery and follow-up was 6.3 (5.8, 7.1) months. The age of the control children was (6.2±1.1) years, including 20 males (76.9%). In severe OSA group, the M (Q1,Q3) of non-rem sleep stage 1 to total sleep time, obstructive apnea hypopnea index, oxygen desaturation index (ODI) and proportion of oxygen saturation (SpO2)<90% during night sleep to total sleep time were 6.8% (5.6%, 8.9%), 1.2 (0.4, 2.4) events/h, 2.1 (0.7, 4.3) events/h and 0(0, 0) after surgery, respectively, which were lower than those before surgery [9.1% (7.5%, 16.8%), 21.6 (14.1, 39.5) events/h, 23.1 (10.2, 36.0) events/h and 0.8% (0, 3.9%), respectively], while non-rem sleep stage 3 to total sleep time%, rem sleep stage to total sleep time% and lowest SpO2 were (24.3±5.7)%, (19.1±3.7)% and 91%(86%, 94%) after surgery, which were higher than those before operation [(19.0±5.3)%, (15.4±3.9)% and 83%(70%, 88%) respectively] (all P values<0.05). The repeated measure ANOVA of SWA intensity in phase N1 showed no interaction between OSA and sleep time course (F=0.02, P=0.997), the main effect of OSA was statistically significant (F=5.12, P=0.040), SWA intensity in children with severe OSA at stage N1 was higher than that of the control group [SWA(severe OSA group before surgery-control group)(95%CI): 0.379,(0.020, 0.739)], while the main effect of sleep time course was not statistically significant (F=1.66, P=0.191). There was no interaction between adenotonsillectomy and sleep time course (F=0.88,P=0.461), the main effect of surgery was statistically significant (F=8.95, P=0.010), SWA intensity of children with severe OSA at N1 stage after surgery was lower than before [SWA(after surgery-before surgery)(95%CI):-0.572(-0.982, -0.162)] and the main effect of sleep time course was statistically significant (F=6.33, P=0.001). The intensity of SWA in the fourth sleep cycle of N1 stage was positively correlated with ODI (r=0.299, P=0.048). Conclusion: The intensity of slow-wave activity at N1 stage is affected by OSA which might be caused by intermittent hypoxia, and adenotonsillectomy significantly reduces SWA intensity at stage N1.

[Effect of metformin combined with intermittent fasting on endoplasmic reticulum stress after cerebral ischemia-reperfusion in mice].

Objective: To explore the effect of metformin combined with intermittent fasting on endoplasmic reticulum stress after cerebral ischemia-reperfusion injury in mice. Methods: One hundred 10-Week-old healthy KM mice of SPF grade, weighing 25-28 g, were divided into 5 groups by the random number table method: sham group, focal cerebral ischemia group (I/R group), intermittent fasting group (IF group), metformin group (Met group), metformin+intermittent fasting group (Met+IF group). In IF group, food was provided ad libitum from 8∶00 to 16∶00 daily, but the mice were fasted for the rest of the time. In Met group, the mice underwent intraperitoneal injection of metformin (10 mg/kg). In Met+IF group, the mice received the same eating method as the IF group and the same method of metformin injection as Met Group. In Sham group, I/R group and IF group, the mice were intraperitoneally injected with equal volume of normal saline. Mice in all groups were not restricted to drinking water. Random plasma glucose and body weight changes in mice during preconditioning were monitored, and a focal cerebral ischemia-reperfusion model was established 14 days later. The cerebral infarction volume was measured after 1 hour of ischemia and 24 hours of reperfusion. The brain tissues of mice were subjected to Western blot to detect the contents of endoplasmic reticulum stress-related proteins, including glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), and apoptosis proteins (Caspase-3 and Cleaved-caspase 3). Results: After different interventions, there was no significant difference in random plasma glucose changes among the four groups (all P<0.05). The blood glucose level of the mice in the Met+IF group was lower than the sham group, I/R group, IF group and Met group (all P<0.05). GRP78/ß-actin in sham group, I/R group, IF group, Met group, IF+Met group were 0.48±0.05, 1.35±0.10, 0.94±0.05, 0.70±0.14, 0.41±0.37, respectively; CHOP/ß-actin were 0.27±0.04, 1.03±0.03, 0.72±0.04, 0.63±0.04, 0.44±0.01, respectively; Caspase-3/ß-actin were 0.51±0.04, 1.04±0.04, 0.83±0.03, 0.76±0.03, 0.63±0.05, respectively; Cleaved-Caspase-3/ß-actin were 0.17±0.06, 1.01±0.20, 0.75±0.06, 0.51±0.12, 0.29±0.08, respectively, with statistically significant differences (all P<0.001). The counts of GRP78-positive cells in the hippocampus immunohistochemistry in the sham group, I/R group, IF group, Met group, and IF+Met group were 53±5, 192±11, 162±12, 140±10, 114±13, respectively, while the counts of CHOP-positive cells were 35±4, 177±12, 120±12, 100±7, 69±10, respectively, with statistically significant differences (all P<0.001). The relative volume of cerebral infarction in I/R group, IF group, Met group and IF+Met group were 0, 0.333±0.046, 0.258±0.023, 0.116±0.039, 0.111±0.039, respectively, and there were statistically significant differences (all P<0.001). Conclusion: Both Metformin and intermittent fasting can alleviate endoplasmic reticulum stress after cerebral ischemia and reperfusion in mice, and the combination of the two has a better effect.

[The relationship between peripheral blood mitochondrial DNA copy number and incident risk of liver cancer: a case-cohort study].

Objective: To investigate the association between peripheral blood mitochondrial DNA copy number (mtDNAcn) and incident risk of liver cancer. Methods: At the baseline of Dongfeng-Tongji (DFTJ) cohort, 27 009 retirees were recruited from Dongfeng Motor Corporation in 2008. After excluding people without baseline DNA, with current malignant tumor and loss of follow-up, 1 173 participants were randomly selected into a sub-cohort by age-and gender-stratified sampling method at a proportion of 5% among all retirees. A total of 154 incident liver cancer cases identified from the cohort before December 31, 2018 (4 cases had been selected into the sub-cohort) were selected to form the case cohort of liver cancer. For the above 1 323 participants, their baseline levels of mtDNAcn in peripheral blood cells were measured by using quantitative real-time PCR method. The restricted cubic spline analysis was used to fit the shape of the association between baseline mtDNAcn and incident risk of liver cancer. The weighted Cox proportional hazards model was used to estimate the hazard ratio (HR) and 95%CI. Results: In this case-cohort study, the median follow-up time was 10.3 years. The restricted cubic spline analysis indicated that the relationship between peripheral blood mtDNAcn and incident risk of liver cancer followed a U-shaped pattern (Pnon-linear<0.05). All case-cohort population were divided into four subgroups by sex-specific quartiles of mtDNAcn levels among sub-cohort participants, when compared to participants in the Q2 subgroup of mtDNAcn, those in the Q1 subgroup (HR=2.00,95%CI:1.08-3.70) and Q4 subgroup (HR=4.11,95%CI:2.32-7.26) both had a significantly elevated risk of liver cancer, while those in the Q3 subgroup (HR=1.05,95%CI:0.54-2.05) had not. There were no significant multiply interaction effects of aging, gender, tobacco smoking, alcohol drinking and history of chronic hepatitis on the above association (Pinteraction>0.05). Conclusion: Both extremely low and high baseline level of mtDNAcn in peripheral blood cells are associated with an increased risk of incident liver cancer, but the underlying mechanisms need to be further clarified.

[Pathological features related to onco-immunity and their clinical significance of pancreatic ductal adenocarcinoma].

Objective: To investigate the tumor immunity-related pathologic features and clinical significance in pancreatic ductal adenocarcinoma (PDAC). Methods: All pathologic materials and clinical information of 192 PDAC patients from the Cancer Hospital of the University of Chinese Academy of Sciences from January 2010 to December 2020 were collected. The onco-immune microenvironment associated morphologic features were evaluated, and MHC-Ⅰ, PD-L1, CD3, and CD8 expression were detected by immunohistochemistry (IHC). Then the correlation between the factors and their influence on prognosis was analyzed. Results: There were 163 cases of non-specific adenocarcinoma (163/192, 84.90%), 18 cases of adeno-squamous carcinoma (18/192, 9.37%), and 11 cases of other rare subtypes (11/192, 5.73%). Perineural invasion was observed in 110 cases (110/192, 57.29%) and vascular invasion in 86 cases (86/192, 44.79%). There were 84 cases (84/182, 46.15%) with severe chronic inflammation. Tumor infiltrating immune cell numbers (TII-N) were increased in 52 cases (52/192, 27.08%). Lymphocytes and plasma cells were the main infiltrating immune cells in 60 cases (60/192, 31.25%), whereas in 34 cases (34/192, 17.71%) the tumors were mainly infiltrated by granulocytes, and 98 cases (98/192, 51.04%) showed mixed infiltration. CD3+T cells were deficient in 124 cases (124/192, 66.31%). CD8+T cells were deficient in 152 cases (152/192, 79.58%). MHC-Ⅰ expression was down-regulated in 156 cases (156/192, 81.25%), and PD-L1 was positive (CPS≥1) in 46 cases (46/192, 23.96%). Statistical analysis showed that TII-N was negatively correlated with vascular invasion (P=0.035), perineural invasion (P=0.002), stage (P=0.004) and long-term alcohol consumption (P=0.039). The type of immune cells correlated positively with chronic pancreatic inflammation (P=0.002), and negatively with tumor differentiation (P=0.024). CD8+T cells were positively correlated with CD3+T cells (P=0.032), MHC-Ⅰ expression (P<0.001) and PD-L1 expression (P=0.001), and negatively correlated with long-term smoking (P=0.016). Univariate analysis showed that histological nonspecific type (P=0.013) and TII-N (P<0.001) were the factors for good prognosis. Vascular invasion (P=0.032), perineural invasion (P=0.001), high stage (P=0.003) and long-term alcohol consumption (P=0.004) were adverse prognostic factors. COX multivariate risk analysis found that TII-N was an independent favorable factor for PDAC, while perineural invasion was an independent adverse risk factor. Conclusions: TII-N is an independent superior prognostic factor for PDAC, and significantly correlated with many factors; chronic alcohol consumption and smoking may inhibit onco-immunity in PDAC patients.

[Application of mechanical debulking in arteriosclerosis occlusive disease of lower extremity].

Objective: To evaluate the effect of mechanical debulking in treating arteriosclerosis occlusive disease of lower extremity. Methods: The clinical data of 52 arteriosclerosis occlusive disease of lower extremity cases treated with Rotarex mechanical debulking system from June 2017 to June 2020 at Department of Intervention Vascular Surgery,Peking University Third Hospital were retrospectively analyzed. There were 37 males and 15 females,aged(69.4±10.1)years(range:47 to 89 years).Lesion length was (21.6±12.9)cm(range:4 to 45 cm),occlusion length was (18.5±11.8)cm(range:4 to 45 cm).The lesion was located in iliac artery(IA) in 6 cases,femoral-popliteal artery(FPA) in 42 cases,and both IA and FPA in 4 cases. All the cases were treated with Rotarex mechanical debulking system. Residual stenosis more than 50% were treated with percutaneous transluminal angioplasty(PTA).Drug coated balloon was used in part of them,and stent was used only when it was necessary. The patient's operation, complications, postoperative target vessel restenosis and reoperation were collected. The paired sample t test and rank sum test was used for data comparison and the postoperative target vessel patency rate was analyzed by Kaplan-Meier survival curve. Results: All the 52 cases obtained technical success. Percutaneous transluminal angioplasty was used in all cases,and drug coated balloon were used in 11 cases. Twenty-six stents were implanted in 24 cases (2 cases implanted 2 stents).Nine stents were implanted in IA and 15 in FPA. The length of stents was (11.3±3.3)cm(range:6 to 23 cm).There were 3 procedure related complications: one of them was acute occlusion in an iliac lesion,and thrombectomy was applied urgently,and the result was good. And the other two were distal embolism. The thrombus were took out with guiding catheter. The hospital stay was (4.8±1.9)days. The ankle brachial index increased from 0.34±0.16 to 0.81±0.16 after treatment(t=-25.160,P<0.01).The Rutherford stages decreased from (M(IQR)) 3(1) to 1(1(Z=-6.825,P<0.01).The median followed up time was 19 months(range:6 to 42 months).Two cases stopped antiplatelet agents during follow-up and which result in acute thrombosis 2 weeks and 2 months later respectively. One of them was treated with percutaneous mechanical thrombectomy and the other one was not for gastrointestinal hemorrhage. Four cases died during follow-up,one case died of lung cancer,one died of abdominal infection,and the other 2 cases died of cardiovascular disease,and no amputation was observed. Target lesion restenosis(TLR) more than 50% occurred in 13 cases during the follow-up. All TLR were observed in FPA,and target lesion revascularization was taken in 3 of them. According to Kaplan-Meier survival curve analysis,half-year,1-year and 2-year cumulative patency rates of target vessels in this group was 94.2%,87.4% and 51.4%, respectively. And half-year and 1-year cumulative patency rates just in FPA cases was 92.9% and 84.3%, respectively. Conclusions: Percutaneous mechanical debulking using Rotarex catheter combining PTA can reduce the use of stents in femoral-popliteal artery. It is safe and effective in treating with arteriosclerosis obliterans of lower extremity.

[Susceptibility of drug-resistant staphylococci isolated from different parts of the ocular anterior segment to common ophthalmic antibiotics].

Objectie To investigate the susceptibility of drug-resistant staphylococci isolated from different parts of the anterior segment to levofloxacin, tobramycin, cefazolin sodium, fusidic acid and clindamycin. Methods: Experimental Study. A total of 67 patients with anterior segment infection (33 cases of conjunctivitis, 6 cases of bacterial keratitis, 7 cases of blepharitis, 9 cases of neonatal dacryocystitis, 9 cases of neonatal dacryocystitis, 1 case of adult dacryocystitis and 11 cases of other infectious eye diseases) were collected from the conjunctival sac, cornea, eyelid margin and lacrimal sac. Minimum inhibitory concentration (MIC) determination of methicillin-resistant Staphylococcus (MRS) strains and ß-lactamase-producing (ß-Lac) strains by a micro-liquid-based method, according to the M100 standard of the American Institute for Clinical and Laboratory Standardization Susceptibility and resistance determinations were made. Data were statistically analyzed using Chi-square or Fisher's exact test. Results: Thirty-five MRS, 30 ß-Lac and 2 ß-Lac MRS isolates were identified from 67 multidrug-resistant Staphylococcus . There were 3, 9, 4, and 19 MRS isolates isolated from the lacrimal sac, cornea, eyelid margin and conjunctival sac, accounting for 3/4, 9/12, 4/8, 19/43 (44.2%) of the isolated sites respectively. There were 1, 3, 3, and 23 ß-Lac isolates, accounting for 1/4, 3/12, 3/8 and 23/43 (53.5%) of the isolated sites, respectively. The highest proportion of ß-Lac isolates isolated from patients with a diagnosis of conjunctivitis was 17 (25.3%) from the conjunctival sac. Among the MRS strains isolated from the cornea and lacrimal sac, 5 (7.5%) and 3 (4.5%) were from patients diagnosed with bacterial keratitis and neonatal tear, respectively. The number of MRS strains and ß-Lac isolates isolated from patients with a diagnosis of blepharitis were both 3 (4.5%) from the lid margin.Among the strains isolated from the eyelid margin and the conjunctival sac, drug-resistant Staphylococcus epidermidis was the main strain, the drug-resistant Staphylococcus aureus was the major isolates in lacrimal sac and cornea. Among the 35 MRS isoaltes, 25, 24, 12, 12, and 11 were sensitive to cefazolin sodium, fusidic acid, levofloxacin, clindamycin and tobramycin, and the sensitivity rates were 71.4%, 68.6%, 34.3%, 34.3% and 31.4%, the difference was statistically significant (χ2=22.756, P<0.001), The sensitivity rates of levofloxacin, tobramycin, cefazolin sodium, fusidic acid and clindamycin against MRS isolates from the anterior segment were both statistically significant differences (χ2=18.493, 11.594, 8.906, 9.841, 16.059; all P<0.05). The susceptibility rates of MRS isolates against five antibiotics was statistically significant differences (χ2=33.080, P<0.001). Among the 30 ß-Lac isolates, 27, 22, 19, 16, and 8 were sensitive to cefazolin sodium, fusidic acid, levofloxacin, tobramycin and clindamycin, and the sensitivity rates were 90.0 % , 73.3%, 63.3%, 53.3% and 26.7%, the difference was statistically significant (χ2=28.280, P<0.001). The sensitivity rates of five antibiotics against ß-Lac isolates from the anterior segment were both statistically significant differences (χ2=50.971, 24.543, 48.147, 44.899, 18.676; all P<0.001). The susceptibility rates of ß-Lac isolates against five antibiotics was statistically significant differences (χ2=23.383, P<0.001). The sensitivity of cefazolin sodium and fusidic acid against ß-Lac isolates were higher than MRS isolates. Conclusions: Cefazolin sodium and fusidic acid may be the best choice for the treatment of drug-resistant Staphylococcus isolated from anterior conjunctival sac, cornea, eyelid margin and lacrimal sac, especially for ß-Lac-producing drug-resistant Staphylococcus infection.

Field-Tunable One-Sided Higher-Order Topological Hinge States in Dirac Semimetals.

Recently, higher-order topological matter and 3D quantum Hall effects have attracted a great amount of attention. The Fermi-arc mechanism of the 3D quantum Hall effect proposed to exist in Weyl semimetals is characterized by the one-sided hinge states, which do not exist in all the previous quantum Hall systems, and more importantly, pose a realistic example of the higher-order topological matter. The experimental effort so far is in the Dirac semimetal Cd_{3}As_{2}, where, however, time-reversal symmetry leads to hinge states on both sides of the top and bottom surfaces, instead of the aspired one-sided hinge states. We propose that under a tilted magnetic field, the hinge states in Cd_{3}As_{2}-like Dirac semimetals can be one sided, highly tunable by field direction and Fermi energy, and robust against weak disorder. Furthermore, we propose a scanning tunneling Hall measurement to detect the one-sided hinge states. Our results will be insightful for exploring not only the quantum Hall effects beyond two dimensions, but also other higher-order topological insulators in the future.

Scratching damages tight junctions through the Akt-claudin 1 axis in atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a common, chronic, severely pruritic, eczematous skin disease that seriously deteriorates the quality of life of patients. Scratching is a cardinal symptom of AD. Although the vicious itch-scratch cycle continues and aggravates skin barrier dysfunction in AD, how scratching induces skin barrier dysfunction through tight junctions remains unclear. AIM: To study the effect of scratching on tight junctions in the itch-scratch cycle. METHODS: Scratching behaviour and skin barrier dysfunction on the neck and back in an AD mouse model were assessed. The expression of tight junction proteins was compared between the neck and back mice, and the mechanisms underlying the involvement of Akt/CLDN1 pathways in this process were explored. RESULTS: We used oxazolone to induce AD on the neck or back of mice. There was significantly more scratching behaviour and more pronounced skin barrier dysfunction with the neck than with the back. Downregulation of claudin-1 (CLDN1) and upregulation of Akt phosphorylation in skin were well correlated with scratching behaviour in this AD model. Furthermore, SC79, an agonist of Akt phosphorylation, could downregulate CLDN1 expression in HaCaT cells. An antagonist of Akt phosphorylation (LY294002) was used to treat the AD mice; this treatment rescued CLDN1 expression through inhibiting Akt phosphorylation in skin, and importantly, also inhibited the scratching behaviour induced by AD. CONCLUSION: The results reveal the underlying mechanism of tight junction damage promoted by scratching in the itch-scratch cycle of AD, and opens a new avenue to pruritus management in AD, through Akt antagonists.

[Application of Rotarex mechanical thrombectomy system in acute lower limb ischemia].

OBJECTIVE: To evaluate the effectiveness and safety of Rotarex mechanical thrombectomy system in treating acute lower limb ischemia. METHODS: From December 2017 to December 2019, the clinical data of 23 acute lower limb ischemia cases treated with Rotarex mechanical thrombectomy system were retrospectively analyzed. There were 14 males and 9 females from 53- to 84-year-old patients and the mean age was (69.1±9.1) years. Duration of symptoms was 6 hours to 14 days (median time 7 days). In the study, 8 acute thromboembolism cases and 15 acute thrombosis cases were included (In which, there was one thromboangiitis obliterans case and two in-stent restenosis cases). In 5 cases, the lesions were located above the groin; in 16 cases, the lesions were located below the groin, and in the other 2 cases, the lesions were located both above and below the groin. All the cases were treated with Rotarex mechanical thrombectomy system. When residual stenosis was greater than 50%, percutaneous transluminal angioplasty (PTA) was used, and stent was used only when it was necessary. Heparin was used 24 h after the procedure, and after that, antiplatelet agents were used in acute thrombosis cases, and oral anti-coagulants were used in acute thromboembolism cases. Doppler ultrasonography was taken during the follow-up. RESULTS: In all the 23 cases, there were 22 successful cases and 1 unsuccessful case, the mean procedure time was (68.2±15.6) min. Percutaneous transluminal angioplasty was used in 18 cases, 7 of which were implanted stents (3 stents were implanted in iliac artery and 4 in superficial femoral artery). There were 3 procedure related complications. The first one was arterial wall injury which resulted in contrast medium extravazation, and in this case, we solved it with prolonged balloon inflation. The second one was distal embolism. We took out the thrombus with guiding catheter. The last one was acute occlusion in a stent, and thrombectomy was applied urgently, and the result was good. Mean hospital stay were (3.6±1.7) days. The ankle brachial index (ABI) increased from 0.25±0.10 to 0.85±0.16 after treatment (t=12.901, P < 0.001). All the patients were followed up for 4.0-28.0 months, and the median time was 12.0 months. One patient stopped antiplatelet agents, which resulted in acute thrombosis 2 months later. Another percutaneous mechanical thrombectomy and PTA were taken. In the failed case, the patient suffered amputation above the knee 3 months later and in another case, the patient died of heart failure 8 months after the procedure. Two target lesion restenosis occurred during the follow-up. Because the patients' symptom was not sever, no procedure was taken. CONCLUSION: Percutaneous mechanical thrombectomy using Rotarex catheter is safe and effective in treating acute lower limb ischemia. For one side, it can restore blood flow to the affected limbs quickly, and for the other, it has the characteristics of minimally invasive and good repeatability. So it should be considered that this me-thod can be widely used for acute lower limb ischemia.

[Application of Rotarex mechanical thrombectomy system in treating in-stent restenosis of lower extremity arteriosclerosis obliterans].

OBJECTIVE: To evaluate the role of Rotarex mechanical thrombectomy system in treating instent restenosis of peripheral artery disease (PAD). METHODS: The clinical data of 7 in-stent restenosis (ISR) cases of lower extremity PAD from June 2017 to Dec 2018 were retrospectively analyzed. There were 5 males and 2 females and the mean age was (70.0±7.6) years from 59.0 to 76.0 years. All the cases were treated by Rotarex mechanical thrombectomy system. In the 7 cases, time interval from the previous stent implantation to ischemia recurrence was 1.0 to 72.0 months, and the median time was 6.0 months. The period from ischemia recurrence to endovascular therapy was 3 days to 2 years, and the median time was 62 days. Rotarex mechanical debulking catheter and percutaneous transluminal angioplasty (PTA) were used in all the cases, and the stent was used only when it was necessary. Anticoagulation was used for 24 hours after procedures and then antiplatelet agents were used as usual. Doppler ultrasonography was taken during the followed-up. RESULTS: All the 7 cases were successful in technology, 3 of which were implanted with new stents for the fracture of the old ones. while for the other four cases, no new stent was implanted. The ankle-brachial index (ABI) increased from 0.31±0.08 to 0.86±0.08 after treatment (t=-12.84, P < 0.001). Thrombectomy was applied urgently in one case because of acute thrombosis in the stent, and the result was good. There was no other complications in hospital. All the patients were followed up for 5.0-22.0 months, and the median time was 14.0 months. No death and amputation occurred during the follow-up. One patient stopped antiplatelet agents because of gastrointestinal bleeding, which resulted in acute thrombosis. in-stent restenosis reappeared in 3 cases. CONCLUSION: Debulking using Rotarex catheter is safe and effective in treating in-stent restenosis of PAD, especially in reducing stents implantation, but is not good at dealing with old thrombus and proliferating intima, and can do nothing about fractured stents and hyperplasia of intima, so it needs to be combined with stents and drug coated balloons.

Theory for the Charge-Density-Wave Mechanism of 3D Quantum Hall Effect.

The charge-density-wave (CDW) mechanism of the 3D quantum Hall effect has been observed recently in ZrTe_{5} [Tang et al., Nature 569, 537 (2019)10.1038/s41586-019-1180-9]. Different from previous cases, the CDW forms on a one-dimensional (1D) band of Landau levels, which strongly depends on the magnetic field. However, its theory is still lacking. We develop a theory for the CDW mechanism of 3D quantum Hall effect. The theory can capture the main features in the experiments. We find a magnetic field induced second-order phase transition to the CDW phase. We find that electron-phonon interactions, rather than electron-electron interactions, dominate the order parameter. We extract the electron-phonon coupling constant from the non-Ohmic I-V relation. We point out a commensurate-incommensurate CDW crossover in the experiment. More importantly, our theory explores a rare case, in which a magnetic field can induce an order-parameter phase transition in one direction but a topological phase transition in other two directions, both depend on one magnetic field.

[Hybrid treatment for symptomatic long-segment chronic internal carotid artery occlusion without stump].

OBJECTIVE: To summarize the preliminary experience of hybrid operation for the treatment of symptomatic long-segment chronic internal carotid artery occlusion (CICAO) without stump. METHODS: Clinical data of 12 patients of symptomatic long-segment CICAO without stump undergoing hybrid operation treatment from July 2015 to December 2017 were retrospectively analyzed. The safety and efficacy of hybrid operation for the treatment of symptomatic long-segment CICAO without stump were preliminarily assessed. CICAO was defined as occlusion time being more than 4 weeks. The primary outcome was defined as any stroke (including ischemic or hemorrhagic) or deaths from any cause after hybrid operation within 30 days. The secondary outcome was defined as successful revascularization and occurrence of >50% in-stent restenosis during the follow-up period. RESULTS: In this group, the symptomatic long-segment CICAO of 11 patients were successfully recanalized. Technical success rate was 91.7% (11/12). The main complication rate was 8.3% (1/12). This patient encountered iatrogenic internal carotid artery cavernous sinus fistula caused by micro-guide wire in the midway of the hybrid operation, the proximal segment of this internal carotid artery was ligated and the iatrogenic internal carotid artery cavernous sinus fistula disappeared in the following digital subtraction angiography image. No patient encountered hemorrhagic stroke and ischemic stroke. No death complications occurred. In this group 10 patients of them were followed up. The follow-up period ranged from 10 to 32 months [mean, (19±9) months]. During the follow-up period, 1 patients developed in-stent restenosis and improved after reoperation of percutaneous transluminal angioplasty by the right size balloon without stenting treatment. CONCLUSION: Hybrid operation for the treatment of highly screened patients with symptomatic long-segment CICAO without stump is safe and effective, could reduce the incidence of complications and improve procedural success rate.

[Evaluation on the effect of comprehensive intervention combined with clinical preventive services and lifestyle adjustment among high-risk populations of cardiovascular disease in Tongxiang City].

Objective: To evaluate the effect of comprehensive intervention combined with clinical preventive services and lifestyle adjustment on high-risk populations of cardiovascular disease. Methods: In 2015, 4 towns (streets) in Tongxiang City, of Zhejiang Province including Heshan Town, Longxiang Street, Wutong Street, and Fengming Street, were selected by using the typical sampling. The towns (streets) were allocated to the intervention group (Heshan Town and Longxiang Street) and the control group (Wutong Street and Fengming Street) by using the cluster random sampling. In each town (street), hypertension patients aged 50 to 74 years old who were taking community medicine management and with a 10-year cardiovascular disease risk ≥10% were recruited as subjects. There were 1 823 subjects in the intervention group and 1 883 in the control group. The intervention group was given a 1-year comprehensive intervention combining clinical preventive services and lifestyle adjustment, while the control group received routine chronic disease management. After the intervention, the final questionnaire investigation was conducted and health physical examination data were obtained. The death, acute coronary heart disease events and stroke incidence were the primary outcomes, and cardiovascular disease-related knowledge and behavior, clinical preventive services utilization, physical changes, blood fat index and 10-year cardiovascular disease risk were the secondary outcomes. The difference-in-difference model was used to evaluate the effects of interventions. Results: The age of subjects in the intervention and control group was (68.76±3.75) and (67.90±4.56) years old, respectively. After 1-year intervention, the incidence of mortality, acute coronary events and stroke in intervention group was 1.65% (30 cases), 0.27% (5 cases) and 2.69% (49 cases), respectively, which showed no statistical difference compared to the control group [1.33% (25 cases), 0.32% (6 cases) and 2.07% (39 cases)]. After adjusting for the age, gender, education, marital status, self-assessed family income level and situation of taking antihypertensive drugs, the difference-in-difference model showed that the body mass index and diastolic blood pressure in the intervention group decreased by 0.33 kg/m(2) and 1.49 mmHg (1 mmHg=0.133 kPa). Compared with the control group, daily vegetable consumption proportion, the awareness rates of aspirin, stains, salt intake, and oil intake increased by 4.76%, 26.22%, 29.56%, 10.80%, and 15.17%, respectively (P<0.05). Conclusion: After the 1-year comprehensive intervention, there was no significant change in primary outcomes among high-risk populations of cardiovascular disease. In secondary outcomes, body mass index and diastolic blood pressure declined and cardiovascular disease-related knowledge awareness increased.

[Comparison study on sensitivity of five ophthalmic antibiotics to common drug-resistant Staphylococci on ocular surface].

Objective: To investigate the in vitro antibacterial sensitivity of levofloxacin, tobramycin, cefazolin sodium, clindamycin and fusidic acid to 67 strains of Staphylococci in ocular surface infection. The purpose of this study is to provide reference for clinical selection of drugs. Methods: Experimental study. Sixth-seven strains of drug-resistant Staphylococci isolated from the Department of Microbiology, Henan Provincial Ophthalmic Hospital during January 2018 and May 2019 were collected. There were 67 strains of Staphylococci including 28 strains of drug-resistant Staphylococcus epidermidi, 17 strains of drug-resistant Staphylococcus aureus, 15 strains of drug-resistant Staphylococcus intermedius and a few other kinds of drug-resistant Staphylococci. The minimum inhibitory concentrations (minimum inhibitory concentration, MIC) of levofloxacin, tobramycin, cefazolin sodium, clindamycin and fusidic acid in 67 strains of drug-resistant Staphylococci were determined by microliquid-based method. The sensitivity was determined according to the American CLSI-M100 standard. The statistical analysis of the data was carried out by using two-dimensional test and Fisher accurate test. Results: Fourteen strains of fusidic acid were sensitive to 17 strains of MRS-Meca-resistant Staphylococcus epidermidis, the difference between fusidic and levofloxacin is statistically significant; 14 strains of cefazolin sodium and 11 strains of fusidic acid were sensitive to 14 strains of ß-Lac enzyme-producing Staphylococcus aureus, and there were significant differences between the two drugs and levofloxacin; 6 strains of cefazolin sodium and 5 strains of fusidic acid were sensitive to 10 strains of MRS-Meca-resistant Staphylococcus intermedius, as compared to levofloxacin, there were significant differences between cefazolin sodium and levofloxacin (P=0.011,0.033). Cefazolin sodium was sensitive to 5 strains of MRS-Meca-positive other drug-resistant Staphylococci, which was significantly different from levofloxacin (P=0.048); 54 and 48 strains of cefazolin sodium and fusidic acid were sensitive to 67 strains of drug-resistant Staphylococci, and the sensitive rates were 80.1% and 71.6%, respectively, which were significantly higher than those of levofloxacin, tobramycin and clindamycin. There were significant statistical differences between drug sensitivity (χ²=18.377,9.940；P=0.000,0.003). Conclusions: The sensitivity of cefazolin sodium and fusidic acid to 67 strains of drug-resistant Staphylococci is better than that of levofloxacin, tobramycin and clindamycin, these findings may provide guidance for the clinical treatment of drug-resistant Staphylococci in ocular infection. (Chin J Ophthalmol, 2020, 56: 621-625).

Anomalous Thermoelectric Effects of ZrTe_{5} in and beyond the Quantum Limit.

Thermoelectric effects are more sensitive and promising probes to topological properties of emergent materials, but much less addressed compared to other physical properties. We study the thermoelectric effects of ZrTe_{5} in a magnetic field. The presence of the nontrivial electrons leads to the anomalous Nernst effect and quasilinear field dependence of thermopower below the quantum limit. In the strong-field quantum limit, both the thermopower and Nernst signal exhibit exotic peaks. At higher magnetic fields, the Nernst signal has a sign reversal at a critical field where the thermopower approaches zero. We propose that these anomalous behaviors can be attributed to the gap closing of the zeroth Landau bands in topological materials with the band inversion. Our understanding to the anomalous thermoelectric properties in ZrTe_{5} opens a new avenue for exploring Dirac physics in topological materials.

[Cerebral hyper perfusion syndrome after carotid artery stenting].

OBJECTIVE: To explore the risk factors, clinical characteristics, precaution and treatment of hyper perfusion syndrome (HPS) after carotid artery stenting (CAS). METHODS: From September 2014 to March 2018, the clinical data of 226 patients with severe carotid stenosis (70%-99%) treated with carotid artery stenting (CAS)at Department of Interventional Radiology and Vascular Surgery, Peking University Third Hospital, were analyzed retrospectively．Five of them developed HPS after CAS．The relationship between the clinical baseline data, imaging characteristics, perioperative management and HPS were assessed. RESULTS: In this group, 5 patients of them (2.21%, 5/226) developed HPS after CAS, and 2 patients of them (0.88%, 2/226) were hyper perfusion induced intracranial hemorrhage (HICH). The 5 patients consisted of 4 men and 1 woman whose age ranged from 58 to 74 years. The symptoms of HPS occurred within 4 hours to 3 days after CAS. Among the 5 cases, the clinical manifestations were that 2 cases with headache, 1 case with delirium,1 case with hemiparesis of left limbs, and 1 case with coma(died ultimately).The main manifestations of case 1 and case 2 were headache in the frontal parietal temporal region of the operative side, accompanied by nausea and vomiting. The symptoms were relieved after blood pressure lowering treatment and mannitol dehydration. The main manifestations of case 3 were excitement and delirium. The symptoms were relieved by a small dose of sedatives, also with blood pressure lowering treatment and mannitol dehydration. The initial symptoms of case 4 were excitement and delirium, accompanied by mild headache of the operative side, and hemiplegia of the contralateral limb occurred within a short time. The main manifestation of case 5 was severe headache and went into deep coma within a short time. This patient died of massive cerebral hemorrhage ultimately. CONCLUSION: HPS is an uncommon but serious complication after CAS. Improving our understanding and heightening vigilance of HPS is necessary. The earlier diagnosis, the earlier treatment.